DE102018122675A1 - Thermal system of a motor vehicle and method of operating the thermal system - Google Patents

Abstract

The invention relates to a thermal system (1, 1a, 1b, 1c) for conditioning the supply air for a passenger compartment and for cooling components of a drive train of a motor vehicle, in particular a thermal management system. The system (1, 1a, 1b, 1c) has a refrigerant circuit (2, 2a, 2b, 2c) with a compressor (3), a first refrigerant-air heat exchanger (4) for transferring heat with ambient air, which as a condenser / Gas cooler and evaporator is operable, a first evaporator operated second refrigerant-air heat exchanger (5) with an upstream first expansion element (6) and a second evaporator operated as a heat exchanger (12) with an upstream second expansion element (13). The refrigerant circuit (2, 2a, 2b, 2c) is also equipped with a condenser / gas cooler operated third refrigerant-air heat exchanger (14) for heating the supply air for the passenger compartment and a third expansion element (15) which between the compressor (3 ) and the first refrigerant-air heat exchanger (4) are formed. The third expansion element (15) is arranged downstream of the third refrigerant-air heat exchanger (14) in the flow direction of the refrigerant.
The invention also relates to methods for operating the thermal system (1, 1a, 1b, 1c).

Description

The invention relates to a thermal system for conditioning the supply air for a passenger compartment and for cooling components of a drive train, in particular a thermal management system, a motor vehicle with a refrigeration ittelkreislauf.
The invention also relates to methods of operation and to a use of the thermal system.

In known from the prior art motor vehicles, the waste heat of the engine is used to heat the supply air for the passenger compartment. The waste heat is transported by means of circulated in an engine coolant circuit coolant to the air conditioner and transmitted there via the heating heat exchanger to the air flowing into the passenger compartment. Known systems with coolant-air heat exchanger, which relate the heating power from the coolant circuit of an efficient internal combustion engine of the vehicle drive, do not generate enough waste heat to heat in particular at low ambient temperatures, the air of the passenger compartment according to the requirements of thermal comfort or that for a comfortable heating reach the required level of the passenger compartment and cover the overall heat demand of the passenger compartment. The same applies to systems in motor vehicles with hybrid drive, that is motor vehicles with both electric motor and internal combustion engine drive, abbreviated as HEV.

In addition, there is a trend toward complete electrification of the drive, such as in vehicles driven purely by electric motor with batteries or fuel cells, that is, electric vehicles, referred to as EV for short. This eliminates the waste heat of the internal combustion engine as a possible heat source for the heating of the air.
The amount of energy that can be stored in the battery of the vehicle is also lower than the amount of energy that can be stored in the form of liquid fuel within the fuel tank. Thus, the power required for the air conditioning of the passenger compartment of an electrically driven vehicle also has a significant influence on the range of the vehicle. The air conditioning system of an electrically driven motor vehicle exerts a very great influence on the efficiency of the operation of the motor vehicle and its energy consumption.

If the total heat demand of the passenger compartment can not be covered by the heat from the engine coolant circuit, additional heating measures, such as electrical resistance heaters, briefly referred to as PTC resistor for "Positive Temperature Coefficient - Thermistor" or fuel heater, are required. Conventional systems with an exclusively designed for cooling the air refrigerant circuit in combination with an electrical resistance heater have a high energy consumption with low outlet temperatures of the supply air for the passenger compartment, especially in regions with low ambient air temperatures on.

A more efficient way to heat the air for the passenger compartment is an air conditioning system with a refrigerant circuit with heat pump function, also referred to as a heat pump, with air as the heat source, in which the refrigerant circuit serves both as a single heating and Zuheizmaßnahme. The refrigerant circuit takes up much more space than a refrigerant circuit designed for cooling the air in combination with electrical resistance heating.
Although an air conditioning system with downstream electrical resistance heating is inexpensive to manufacture and is used in any motor vehicles, but has a very large demand for electrical energy, since the supply air for the passenger compartment when overflowing an evaporator of the refrigerant circuit initially cooled and / or dehumidified and then by means the electrical resistance heating, which transfers the heat directly to the supply air or a coolant circuit, is heated.
Although the operation of a conventional refrigerant circuit to be operated as a heat pump is efficient, it requires a great deal of installation space, even at positions inside the motor vehicle which have no installation space provision for the air conditioning. In the heat pump mode operable refrigerant circuits are on the one hand due to the large number of components, such as heat exchangers and necessary valves or expansion organs, very complex. On the other hand, the refrigerant circuits on so-called outdoor heat exchanger for receiving heat from the ambient air and for evaporation of the refrigerant, in which compared to the operation in the refrigeration system, a reversal of the flow direction of the refrigerant for operation in heat pump mode is necessary. However, the flow direction of the refrigerant can be reversed only when the compressor of the refrigerant is deactivated, which can lead to an unwanted decrease or increase the discharge temperature of the supply air for the passenger compartment.

All air conditioning systems of motor vehicles with a heat pump to be operated refrigerant circuit is peculiar that when operating in the refrigeration system, the heat required for evaporation of the refrigerant from the supply air for the passenger compartment or a Coolant circuit, for example, for controlling the temperature of electrical components of the drive train, such as the traction battery is recorded. In a heat exchanger operated as a condenser / gas cooler, the heat absorbed during the evaporation is released to the environment at a higher temperature level. In an operation of the refrigerant circuit in the heat pump mode, the heat required for the evaporation of the refrigerant heat from a waste heat source, such as the ambient air or the coolant circuit, for example, for controlling the temperature of electrical components of the drive train, recorded. In a so-called interior or passenger compartment condenser / gas cooler arranged heat exchanger, the heat is released at a high temperature level to the supply air of the passenger compartment.

Related to the prior art air-to-air heat pumps, which are for the combined refrigeration system mode and heat pump mode, that is, for a heating mode, as well as for a Nachheizmodus, also referred to as reheat mode, formed and absorb the heat from the ambient air, the refrigerant vaporized by the absorption of heat from the ambient air, which is transmitted in a refrigerant-air heat exchanger either directly or in a refrigerant-refrigerant heat exchanger and thus indirectly to the refrigerant. The ambient air thus serves as a heat source for the evaporation of the refrigerant. The performance and efficiency of the system depends in particular on how much heat is available at which temperature level for evaporating the refrigerant.
The conventional air-to-air heat pumps have, in addition to the heat exchanger for heat transfer between the refrigerant and the ambient air, a heat exchanger for supplying heat from the conditioned air of the passenger compartment to the refrigerant and a heat exchanger for heat transfer from the refrigerant to the conditioned air for the passenger compartment , The services are transferred between the refrigerant and the air.
In the so-called "reheat" or post-heating mode, the air to be supplied to the passenger compartment is cooled, dehumidified and then slightly heated again. In this operating mode, the required reheating power is lower than the required cooling capacity for cooling and dehumidifying the air.

The heat exchanger for heat transfer between the refrigerant and the ambient air of the air-to-air heat pump, also referred to as ambient heat exchanger, is outside the housing of the air conditioning system, especially outside the air conditioner, arranged on the front side of the motor vehicle and is particularly acted upon by the airstream with air , When operating the refrigerant circuit in the refrigeration system mode, the ambient heat exchanger is operated as a condenser / gas cooler for heat transfer from the refrigerant to the ambient air and the operation of the refrigerant circuit in the heat pump mode as an evaporator for heat absorption from the refrigerant from the ambient air.
When operating the refrigerant circuit in the heat pump mode and ambient air as a heat source at temperatures of air in the range of 0 ° C and below 0 ° C, the risk of icing of the heat transfer surface of the operated as an evaporator heat exchanger, which limits the performance of the heat exchanger. As a result of the absorption of heat from the air, the relative humidity of the cooled air increases. When falling below the dew point of the water vapor present in the air is condensed out and deposited as water on the heat transfer surface. The water condensed out of the air at the heat transfer surface solidifies to ice at surface temperatures in the range of 0 ° C and below 0 ° C. The increasing ice sheet reduces the air side heat transfer surface as well as the air side heat transfer and thus the transferable power between the air and the evaporating refrigerant, which leads to a reduction in the efficiency of the entire air conditioning system. Usually, the maximum temperature difference between the temperature of the entering into the ambient heat exchanger air and the temperature of the refrigerant is limited, which in turn limits the maximum of the ambient heat absorbable heat.
Due to the necessary avoidance of icing of the heat transfer surface of the ambient heat exchanger, it is not possible at temperatures of air in the range of 0 ° C and below 0 ° C even when designed as air-to-air heat pumps air conditioning systems to heat the passenger compartment sufficiently, if only the Ambient air is used as a heat source, so that additional heating measures are required. Eligible electrical resistance heaters are not energy efficient and are rarely commissioned.

In order to increase the energy consumption and the efficiency of the operation of the motor vehicle, conventional air conditioning systems are used with heat pump function, which can use different heat sources. In particular, electric vehicles or hybrid vehicles due to training with additional components such as a high-voltage battery, an internal charger, a transformer, an inverter and the electric motor, usually a higher refrigeration demand than motor vehicles with a pure internal combustion engine drive or an additional Cooling demand on. In order in particular to comply with the permitted temperature limits of the high-voltage battery, which are usually in the range of 0 ° C to 35 ° C, in particular between 20 ° C and 35 ° C, systems with heat pump function are preferably used, which implement active cooling concepts and heating concepts serve. The additional components of the electric drive train can be used, for example, as heat sources.
In this case, the refrigerant circuit of the known from the prior art air conditioning systems with heat pump function low pressure side usually with a refrigerant-refrigerant heat exchanger, also referred to as a chiller, which connects a coolant circuit for controlling the temperature of the components of the electric drive train with the refrigerant circuit thermally. The circulating coolant in the coolant circuit can be used as a heat source for the refrigerant. With the so-called low-temperature coolant circuit, the waste heat absorbed by the coolant can also be transferred directly to the environment via a low-temperature heat exchanger, without operating the refrigerant circuit. Due to the large number of components to be provided for such an air conditioning system, the complexities also increase the system costs of the motor vehicle.

In the DE 10 2017 114 136 A1 For example, a motor vehicle having a thermal system comprising a refrigerant circuit and a coolant circuit will be described. The refrigerant circuit and the coolant circuit are thermally connected to each other via a heat exchanger. The refrigerant circuit is used to temper the supply air for a passenger compartment and to absorb heat from the coolant circuit, which is used in particular for cooling components of the electric drive train, such as a battery of the motor vehicle.

The object of the invention is to provide a thermal system or air conditioning system with sufficient cooling capacity and sufficient heat output for the supply air of the passenger compartment, in particular for motor vehicles with an electric or a combined electric and internal combustion engine drive. The system should have a diverse potential of possible operating modes with a minimum number of components of the refrigerant circuit, such as heat exchangers and expansion devices, compared to known systems. This is intended, for example, to maximize the potential range of, in particular, electrically powered motor vehicles with minimal monetary outlay. In this case, the system, in particular the refrigerant circuit with heat pump functionality, very well controllable and be optimally and efficiently operable in all possible operating modes and under all possible external conditions and needs. The consumption of electrical energy during operation should be minimal.
In addition, the manufacturing, maintenance and operating costs and the required installation space of the system should be minimal.

The object is achieved by the subject matter and the method having the features of the independent patent claim. Further developments are specified in the dependent claims.

The object is achieved by an inventive thermal system for conditioning the supply air for a passenger compartment and for cooling components of a drive train of a motor vehicle, in particular a thermal management system. The components of the drive train of the motor vehicle can serve as a heat source depending on the needs and operating mode of the system.
The thermal system has a refrigerant circuit with a compressor, a first, as condenser / gas cooler and evaporator operable refrigerant-air heat exchanger, operated as a first evaporator second refrigerant-air heat exchanger with an upstream in the flow direction of the refrigerant first expansion element and a second Evaporator operated heat exchanger with a upstream in the flow direction of the refrigerant second expansion element.
The first refrigerant-air heat exchanger can be operated either as an evaporator or as a condenser / gas cooler depending on the needs and operating mode of the system, in particular the refrigerant circuit. In this case, the refrigerant-air flow through the first refrigerant-air heat exchanger advantageously independent of the operating mode of the system unidirectional or monodirectional.
If the liquefaction of the refrigerant occurs in subcritical operation, such as with the refrigerant R134a or in certain ambient conditions with carbon dioxide, the heat exchangers are referred to as a condenser. Part of the heat transfer takes place at a constant temperature. In supercritical operation or supercritical heat in the heat exchanger, the temperature of the refrigerant steadily decreases. In this case, the heat exchanger is also referred to as a gas cooler. Supercritical operation may occur under certain environmental conditions or operations of the refrigerant cycle with, for example, the refrigerant carbon dioxide.

According to the concept of the invention, the refrigerant circuit also has a condenser / gas cooler operated third refrigerant air heat exchanger for heating the supply air for the passenger compartment and a third expansion element, which are arranged between the compressor and the first refrigerant-air heat exchanger. In this case, the third expansion element is arranged downstream of the third refrigerant-air heat exchanger in the flow direction of the refrigerant.

According to a development of the invention, the first evaporator operated second refrigerant-air heat exchanger with the first expansion element within a first flow path and operated as a second evaporator heat exchanger with the second expansion element within a second flow path of the refrigerant circuit are arranged. The flow paths are in each case extending from a branch point to an opening point of the refrigerant circuit, arranged parallel to one another and, depending on requirements, individually or in parallel with one another with refrigerant.

According to a preferred embodiment of the invention, the refrigerant circuit has a bypass flow path around the first refrigerant-air heat exchanger. The bypass flow path is extending from a branch point to an orifice point, arranged parallel to the first refrigerant-air heat exchanger. The branch point of the bypass flow path is preferably formed between the third refrigerant-air heat exchanger and the third expansion element. The discharge point of the bypass flow path is advantageously arranged between the first refrigerant-air heat exchanger and the first expansion element or the second expansion element, that is to say in the flow direction of the refrigerant upstream of the discharge point of the flow paths with the heat exchangers operated as evaporators.
Within the bypass flow path, a valve for opening and closing the bypass flow path is preferably formed.

A particular advantage of the invention is that the branch point of the bypass flow path is designed as a combined three-way valve with expansion functionality in the direction of the first refrigerant-air heat exchanger and with shut-off functionality in the direction of the bypass flow path. Thus, the third expansion element of the refrigerant circuit and the valve of the bypass flow path are integrated with the branch point of the bypass flow path in a component.

According to a preferred embodiment of the invention, the second heat exchanger operated as a heat exchanger is designed as a refrigerant-refrigerant heat exchanger and arranged within a coolant circuit. The coolant circuit has a heat exchanger for receiving heat from the components of the drive train, in particular for cooling the components of the drive train.

In addition, the refrigerant circuit may be formed with an internal heat exchanger. Under the internal heat exchanger is an internal circulation heat exchanger to understand, which serves the heat transfer between the refrigerant at high pressure and the refrigerant at low pressure. In this case, for example, on the one hand, the liquid refrigerant after the condensation or liquefaction further cooled and on the other hand, the suction gas overheated in front of the compressor. The inner heat exchanger is arranged on the low pressure side within the first flow path in the flow direction of the refrigerant after the operated as an evaporator second refrigerant-air heat exchanger.

According to a first alternative embodiment of the invention, the inner heat exchanger is arranged on the high pressure side between the discharge point of the bypass flow path and the branch point of the flow paths with the heat exchangers operated as an evaporator.
According to a second alternative embodiment of the invention, the inner heat exchanger is arranged on the high pressure side between the first refrigerant-air heat exchanger and the discharge point of the bypass flow path.
According to a third alternative embodiment of the invention, the inner heat exchanger is arranged on the high pressure side within the first flow path in the flow direction of the refrigerant upstream of the first expansion element.

Furthermore, the refrigerant circuit may be formed with a low-pressure side arranged refrigerant collector, also referred to as an accumulator.

According to a development of the invention, the thermal system on an air conditioner with a blower for conveying the supply air for the passenger compartment through a housing. In this case, the second refrigerant-air heat exchanger of the refrigerant circuit is preferably formed engaging the entire flow cross-section of the housing.
The housing preferably has a first flow path and a second flow path, which are arranged parallel to one another and, depending on requirements, can be acted upon individually or in parallel with the supply air. Within the first flow path, the third refrigerant-air heat exchanger and an auxiliary heating heat exchanger are advantageously arranged in the flow direction of the supply air. The second flow path is provided as a bypass to the first flow path.

The object is also achieved by an inventive method for operating a conceptional thermal system, in particular a thermal management system, a motor vehicle for operation in a refrigeration system mode, in a heat pump mode and in a Nachheizmodus for conditioned supply air of a passenger compartment.

According to one conception of the invention, when the system is operating in a heat pump mode or afterheating mode, the refrigerant is heated from a high pressure level to the passenger compartment supply air flowing through the third expansion device located between the third refrigerant air heat exchanger and the first refrigerant air heat exchanger Low pressure level relaxed and vaporized while flowing through the operated as an evaporator first refrigerant air heat exchanger with absorption of heat from the ambient air. In this case, heat is transferred from the refrigerant to the supply air for the passenger compartment when flowing through the third refrigerant-air heat exchanger.

According to a development of the invention, a mass flow of the refrigerant is conducted to the compressor by completely opening the second refrigerant-air heat exchanger operated as the first evaporator and / or the heat exchanger upstream as the second evaporator without pressure loss.

According to a further concept of the invention, the refrigerant is passed during operation of the system in a heat pump mode or Nachheizmodus for heating the supply air of the passenger compartment through the bypass flow path to the first refrigerant-air heat exchanger and the flow of the first evaporator operated as the second refrigerant air Heat exchanger vaporized by absorbing heat from the supply air and / or operated as a second evaporator heat exchanger with the absorption of heat from the components of the drive train. In this case, heat is transferred from the refrigerant to the supply air for the passenger compartment when flowing through the third refrigerant-air heat exchanger.

According to a preferred embodiment of the invention, a mass flow of the refrigerant by position of the first evaporator operated second refrigerant-air heat exchanger and the second evaporator operated heat exchanger upstream expansion elements on the heat exchanger for receiving heat from the supply air for the passenger compartment and / or Split components of the powertrain.

The advantageous embodiment of the invention allows the use of the thermal system as an air conditioning system of a motor vehicle for conditioning the supply air for the passenger compartment and for conditioning components of the drive train and electronic components.

• - das in unterschiedlichen Betriebspunkten, insbesondere bei einem Betrieb im Wärmepumpenmodus beziehungsweise Heizmodus oder Nachheizmodus, effizient betreibbare Wärmemanagementsystem führt zu einem geringeren Energieverbrauch und damit zu einer höheren Reichweite des Kraftfahrzeugs,
• - stufenloser Wechsel zwischen den Betrieben im Wärmepumpenmodus beziehungsweise Heizmodus und Kälteanlagenmodus ohne Abschalten des Verdichters,
• - hoher Grad der Abwärmenutzung, insbesondere der Komponenten des Antriebsstranges als Wärmequelle, mit großer möglicher Heizleistung, dabei sind zudem die Werte des Drucks des Kältemittels bei der Verdampfung beziehungsweise des Saugdrucks und damit der Saugdichte hoch, sodass auch der Massenstrom des Kältemittels groß ist,
• - einfach konzipiertes System mit minimaler Anzahl an Komponenten sowie minimalem Bauraum, unter anderem ohne Umkehr der Strömungsrichtung des Kältemittels im als Kondensator/Gaskühler oder Verdampfer betreibbaren Umgebungswärmeübertrager,
• - damit einfaches Ölmanagementsystem durch Vermeiden von Ölfallen und
• - geringe Kosten bei der Herstellung und Wartung sowie während des Betriebs.

The thermal system according to the invention and the methods for operating the system have in summary various advantages:

• the thermal management system operable efficiently at different operating points, in particular when operating in heat pump mode or heating mode or reheating mode, leads to a lower energy consumption and thus to a higher range of the motor vehicle,
• - continuous change between the plants in heat pump mode or heating mode and refrigeration system mode without switching off the compressor,
• high degree of waste heat utilization, in particular of the components of the drive train as heat source, with great possible heating power, besides, the values of the pressure of the refrigerant in the evaporation or the suction pressure and thus the suction density are high, so that the mass flow of the refrigerant is large,
• a simply designed system with a minimal number of components and minimal installation space, including without reversing the direction of flow of the refrigerant in the ambient heat exchanger which can be operated as a condenser / gas cooler or evaporator,
• - For easy oil management system by avoiding oil traps and
• - low production and maintenance costs as well as during operation.

The thermal system or the air conditioning system, in particular the refrigerant circuit, is independent of the refrigerant used and thus also designed for R134a, R744, R1234yf or other refrigerants.

• 1: mit einem als Verdampfer oder als Kondensator/Gaskühler betreibbaren ersten Kältemittel-Luft-Wärmeübertrager, einem als Verdampfer betriebenen zweiten Kältemittel-Luft-Wärmeübertrager sowie einem als Verdampfer betriebenen Kältemittel-Kühlmittel-Wärmeübertrager sowie den Wärmeübertragern jeweils zugeordneten Expansionsorganen und einem als Kondensator/Gaskühler betriebenen dritten Kältemittel-Luft-Wärmeübertrager, bei einem Betrieb
• 2: in einem Kälteanlagenmodus für die Zuluft des Fahrgastraums,
• 3: in einem Kälteanlagenmodus für die Zuluft des Fahrgastraums sowie einem Kühlmodus von Komponenten des Antriebsstrangs,
• 4: in einem Wärmepumpenmodus zum Erwärmen der Zuluft des Fahrgastraums unter Aufnahme von Wärme aus der Umgebungsluft,
• 5: in einem Wärmepumpenmodus zum Erwärmen der Zuluft des Fahrgastraums sowie einem Kühlmodus von Komponenten des Antriebsstrangs,
• 6: in einem Nachheizmodus für die Zuluft des Fahrgastraums,
• 7: in einem Nachheizmodus für die Zuluft des Fahrgastraums sowie einem Kühlmodus von Komponenten des Antriebsstrangs,
• 8: in einem Nachheizmodus für die Zuluft des Fahrgastraums sowie einem Kühlmodus von Komponenten des Antriebsstrangs gemäß 7 mit zusätzlicher Übertragung von Wärme an die Umgebung,
• 9: in einem Abtaumodus des als Kondensator/Gaskühler betriebenen ersten Kältemittel-Luft-Wärmeübertragers und
• 10: in einem Kühlmodus von Komponenten des Antriebsstrangs,
• 11: mit einem Kältemittelkreislauf ähnlich 1 mit einem inneren Wärmeübertrager, welcher hochdruckseitig in Strömungsrichtung des Kältemittels vor den Expansionsorganen der als Verdampfer betriebenen zweiten Kältemittel-Luft-Wärmeübertrager sowie Kältemittel-Kühlmittel-Wärmeübertrager und niederdruckseitig nach dem als Verdampfer betriebenen zweiten Kältemittel-Luft-Wärmeübertrager angeordnet ist,
• 12: mit einem Kältemittelkreislauf ähnlich 11, wobei der innere Wärmeübertrager hochdruckseitig derart eingebunden ist, dass das durch einen Bypass geleitete Kältemittel den inneren Wärmeübertrager umströmt, und
• 13: mit einem Kältemittelkreislauf ähnlich 11, wobei der innere Wärmeübertrager hochdruckseitig in Strömungsrichtung des Kältemittels vor dem Expansionsorgan des als Verdampfer betriebenen zweiten Kältemittel-Luft-Wärmeübertrager angeordnet ist.

Further details, features and advantages of embodiments of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings.
Each show a thermal system of a motor vehicle with an air conditioner and a refrigerant circuit for conditioning the supply air for the passenger compartment and for cooling components of the drive train:

• 1 with a operated as an evaporator or as a condenser / gas cooler first refrigerant-air heat exchanger, operated as an evaporator second refrigerant air heat exchanger and operated as an evaporator refrigerant refrigerant heat exchanger and the heat exchangers respectively associated expansion elements and a condenser / gas cooler operated third refrigerant-air heat exchanger, in one operation
• 2 in a refrigeration mode for the supply air of the passenger compartment,
• 3 in a passenger compartment supply chiller system and a powertrain cooling mode,
• 4 in a heat pump mode for heating the supply air of the passenger compartment while absorbing heat from the ambient air,
• 5 in a heat pump mode for heating the supply air of the passenger compartment as well as a cooling mode of components of the drive train,
• 6 in a reheating mode for the incoming air of the passenger compartment,
• 7 in a reheating mode for the supply air of the passenger compartment as well as a cooling mode of components of the drive train,
• 8th in a preheat mode for the supply air of the passenger compartment and a cooling mode of components of the drive train according to 7 with additional transfer of heat to the environment,
• 9 in a defrost mode of operated as a condenser / gas cooler first refrigerant air heat exchanger and
• 10 in a cooling mode of powertrain components,
• 11 : similar to a refrigerant circuit 1 with an internal heat exchanger, which is arranged on the high pressure side in the flow direction of the refrigerant upstream of the expansion organs of the second refrigerant-air heat exchanger operated as an evaporator and refrigerant-refrigerant heat exchanger and low-pressure side after the operated as an evaporator second refrigerant-air heat exchanger
• 12 : similar to a refrigerant circuit 11 , wherein the inner heat exchanger is integrated high pressure side such that the bypassed refrigerant flows around the inner heat exchanger, and
• 13 : similar to a refrigerant circuit 11 , wherein the inner heat exchanger is arranged on the high pressure side in the flow direction of the refrigerant upstream of the expansion element of the operated as an evaporator second refrigerant-air heat exchanger.

Out 1 goes a thermal system 1 with a refrigerant circuit 2 for conditioning the supply air for the passenger compartment and cooling components of the drive train of a motor vehicle.
The refrigerant circuit 2 is with a compressor 3 , a first refrigerant-air heat exchanger operable as an evaporator or as a condenser / gas cooler 4 , operated as a first evaporator second refrigerant-air heat exchanger 5 and a second refrigerant evaporator operated refrigerant-refrigerant heat exchanger 12 and the heat exchangers 4 . 5 . 12 respectively associated expansion organs 6 . 13 . 15 and a condenser / gas cooler operated third refrigerant-air heat exchanger 14 educated.

The first evaporator 5 is with the upstream expansion organ 6 within a first flow path 7 arranged, which is a branch point 8th up to an estuarine site 9 extends. The trained as a refrigerant-air heat exchanger first evaporator 5 is configured for conditioning, in particular for cooling and / or dehumidifying the supply air for the passenger compartment. Within the first flow path 7 , in particular between the evaporator 5 and the confluence point 9 is also a check valve 10 designed according to the operating mode of the refrigerant circuit 2 a return flow of refrigerant into the first flow path 7 to prevent.
The second evaporator 12 is with the upstream expansion organ 13 within a second flow path 11 arranged, which is also from the branch point 8th to the confluence point 9 extends and thus parallel to the first flow path 7 runs. The second as a refrigerant-refrigerant heat exchanger of the refrigerant circuit 2 trained second evaporator 12 is to transfer heat from components of the powertrain to the refrigerant of the refrigerant circuit 2 configured.
The expansion organs 6 . 13 are preferably designed as expansion valves, with which the mass flow of the refrigerant in partial mass flows through the flow paths 7 . 11 can be split. In this case, the mass flow through the evaporator 5 . 12 infinitely adjustable between 0% and 100%. The partial mass flows are at the discharge point 9 merged. The compressor 3 sucks the refrigerant depending on the operating mode of the system 1 and the refrigerant circuit 2 from the flow paths 7 . 11 and promote that Refrigerant to the third refrigerant-air heat exchanger 14 ,

Between the operated as a condenser / gas cooler third refrigerant-air heat exchanger 14 for transferring heat to the supply air for the passenger compartment and the first refrigerant-air heat exchanger 4 for transferring heat between the refrigerant and ambient air, also referred to as ambient heat exchanger, is the third expansion element 15 arranged. By means of the third expansion organ 15 can be the first refrigerant-air heat exchanger 4 Depending on requirements, refrigerant can be supplied at high pressure level, at a medium pressure level or at low pressure level. In this case, on the one hand, the heat of a present at high pressure level refrigerant with each operated as a condenser / gas cooler first refrigerant-air heat exchanger 4 and third refrigerant-air heat exchanger 14 be transmitted either to the supply air for the passenger compartment and / or to the ambient air. That between the heat exchangers 4 . 14 arranged and designed as an expansion valve third expansion element 15 may either be fully open to pass the refrigerant without significant pressure loss, or may be set such, between the high pressure level and a low pressure level of the refrigerant circuit 2 infinitely adjust existing average pressure level. Thus, the heat to be transferred to the supply air for the passenger compartment and to the ambient air quantities of heat can be adjusted. On the other hand, the first refrigerant-air heat exchanger 4 by means of the setting of the third expansion organ 15 be acted upon at medium pressure level or at low pressure level and thereby operated as an evaporator. Consequently, by means of the adjustment of the third expansion organ 15 in the first refrigerant-air heat exchanger 4 Depending on the need heat from the refrigerant can be absorbed or delivered, which is very sensitive adjustable without, for example, the temperature of the supply air for the passenger compartment noticeably reduced.

The refrigerant circuit 2 also has a bypass flow path 16 on which is from a branch point 17 up to an estuarine site 18 extends and bypasses the first refrigerant-air heat exchanger 4 is trained. The branch point 17 is between the third refrigerant-air heat exchanger 14 and the third expansion organ 15 of the first refrigerant-air heat exchanger 4 arranged while the confluence 18 between the first refrigerant-air heat exchanger 4 and the branch office 8th the flow paths 7 . 11 is trained. Inside the bypass flow path 16 is also a valve 19 , in particular a two-way valve or a shut-off valve, for opening or closing the bypass flow path 16 intended. Furthermore, between the refrigerant-air heat exchanger 4 and the confluence point 18 a check valve 20 designed according to the operating mode of the refrigerant circuit 2 a return flow through the bypass flow path 16 conducted refrigerant in the refrigerant-air heat exchanger 4 to prevent.
In an alternative embodiment, the branch point is 17 in conjunction with the third expansion organ 15 and the valve 19 as a combined three-way valve with expansion functionality in the direction of the first refrigerant-air heat exchanger 4 as well as with shut-off / opening functionality in the direction of the bypass flow path 16 , preferably within a common housing.

The refrigerant circuit 2 also has an accumulator 21 for separating and collecting liquid refrigerant and various sensors 22a . 22b . 22c . 23a . 23b on. The accumulator 21 is on the low pressure side of the refrigerant circuit 2 in front of the inlet of the compressor 3 intended. The sensors 22a . 22b . 22c are called pressure-temperature sensors and the sensors 23a . 23b are designed as temperature sensors.
Here is a first pressure-temperature sensor 22a for determining the pressure and temperature of the hot gas and for controlling the high pressure of the refrigerant at the outlet of the compressor 3 arranged.
A second, in the flow direction of the refrigerant after the first refrigerant-air heat exchanger 4 provided pressure-temperature sensor 22b serves for the operation of the refrigerant circuit 2 in a heat pump mode for controlling the temperature or the pressure of the refrigerant in the refrigerant-air heat exchanger 4 as well as during operation of the refrigerant circuit 2 in a reheat mode for regulating the medium pressure level. The refrigerant may have states in the two-phase region and thus have vapor and liquid droplets. The power limitation is used in particular to freeze the heat transfer surface of the refrigerant-air-heat exchanger 4 to avoid.
A third, in the flow direction of the refrigerant after the refrigerant-refrigerant heat exchanger 12 arranged pressure-temperature sensor 22c is configured to overheat the refrigerant at the outlet of the evaporator 12 to regulate. Especially when operating the refrigerant circuit 2 in a heat pump mode or reheat mode and the absorption of heat from the ambient air in the refrigerant-air heat exchanger 4 may be the refrigerant-refrigerant heat exchanger 12 possibly with refrigerant at a slightly lower pressure level than the refrigerant-air heat exchanger 4 operate. In addition, there is the Possibility that in the refrigerant-refrigerant heat exchanger 12 no heat is transferred to the refrigerant. It is always to prevent the compressor 3 drawing in liquid refrigerant.
A first, in the flow direction of the refrigerant after the second refrigerant-air heat exchanger 5 arranged temperature sensor 23a is to control the overheating of the refrigerant at the outlet of the evaporator 5 intended. Furthermore, a second, in the flow direction of the refrigerant after the third refrigerant-air heat exchanger 14 arranged temperature sensor 23b during operation of the refrigerant circuit 2 in a heat pump mode to control the subcooling of the refrigerant.

The components of the powertrain are using a heat exchanger 25 tempered, in particular cooled. The heat exchanger 25 can be designed as part of a coolant circuit. Within the coolant circuit is also the refrigerant-refrigerant heat exchanger 12 of the refrigerant circuit 2 integrated. The refrigerant-refrigerant heat exchanger 12 connects the refrigerant circuit 2 thermally with the coolant circuit. The heat transferred from the components of the powertrain to the coolant heat is in the refrigerant-coolant heat exchanger 12 delivered to the refrigerant. This allows the components of the powertrain as heat sources for the refrigerant circuit 2 be used. The coolant is conveyed by means of a conveying device, not shown, especially a coolant pump, through the coolant circuit.
The thermal system 1 Thus, for example, allows operation in a heating mode or in a heat pump mode, in which the heat absorbed by the coolant of the coolant circuit from the components of the drive train waste heat in the refrigerant-coolant heat exchanger 12 is provided as heat of vaporization for the refrigerant. The functionality of the heat recovery contributes to the improvement of the overall energy efficiency and heat efficiency of the motor vehicle.

In 1 is further an arrangement of the third, operated as a condenser / gas cooler refrigerant air heat exchanger 14 of the refrigerant circuit 2 and a Zusatzheizwärmeübertragers 35 for transferring heat to the supply air for the passenger compartment within an air conditioner 30 shown.
The air conditioner 30 has a housing 31 with a non-illustrated inlet for circulating air from the passenger compartment and an inlet, not shown, for fresh air from the environment. The inlets are opened or closed as required by means of a louver, wherein the flow cross sections of the inlets can be locked or released continuously between 0% and 100%.
One from a blower 32 By at least one of the inlets sucked air mass flow is first through the second, operated as an evaporator refrigerant-air heat exchanger 5 of the refrigerant circuit 2 directed. Depending on the need and position of a louver 33 , in particular a temperature flap, which, when flowing through the heat exchanger 5 conditioned air on the one hand into a first flow channel 34 and thereby by the condenser / gas cooler operated third refrigerant-air heat exchanger 14 of the refrigerant circuit 2 and a Zusatzheizwärmeübertrager 35 flow and are heated. The third refrigerant air heat exchanger 14 of the refrigerant circuit 2 and the Zusatzheizwärmeübertrager 35 are successively arranged to be acted upon by the supply air for the passenger compartment and cover the entire flow cross-section of the first flow channel 34 , The third refrigerant air heat exchanger 14 is due to the arrangement within the air conditioner 30 also referred to as internal condenser / gas cooler. On the other hand, when flowing through the heat exchanger 5 conditioned air into a second flow channel 36 , which as a bypass 36 to the first flow channel 34 is formed, introduced and thus to the heat exchanger 14 . 35 passed by. The flow cross sections of the flow channels 34 . 36 can be locked or opened steplessly between 0% and 100%. The through the flow channels 34 . 36 guided mass flows of supply air are then mixed depending on the operating mode or run unmixed in the flow direction in the passenger compartment.

With the additional heating heat exchanger 35 , Preferably an additional electric heater, such as a resistance heater, or a heat exchanger of a refrigerant circuit, heat can be provided in addition and heat of the refrigerant when needed and insufficient heat and a reduced amount of heat can be compensated.

In the 2 to 11 are different operating modes of the thermal system 1 out 1 shown. The components of the refrigerant circuit which are each supplied with refrigerant 2 , in particular the corresponding refrigerant pipes are marked as solid lines. The unbuffered components and sections of the refrigerant circuit 2 are marked with dashed lines.

2 shows the thermal system 1 when operating in a refrigeration mode for the supply air of the passenger compartment.
The by the air conditioner 30 in the flow direction 37a Guided supply air for the passenger compartment is when overflowing the heat transfer surface of the operated as an evaporator second refrigerant-air heat exchanger 5 cooled and / or dehumidified. The louver 33 is the first flow channel 34 arranged close. The third refrigerant air heat exchanger 14 is not supplied with the supply air, which through the second flow channel 36 around the heat exchanger 14 . 35 is led around. This is neither in the third refrigerant-air heat exchanger 14 still in the additional heating heat exchanger 35 Transfer heat.
That between the third refrigerant-air heat exchanger 14 and operated as a condenser / gas cooler first refrigerant-air heat exchanger 4 arranged third expansion organ 15 is fully open so that the refrigerant is the expansion organ 15 happens without pressure loss. The refrigerant from the refrigerant circuit 2 dissipated heat is in the first refrigerant-air heat exchanger 4 completely to the flow direction 37b transmitted ambient air transmitted. The bypass flow path 16 is closed and is not flowed through by refrigerant.
In the first expansion organ 6 of the first evaporator 5 the refrigerant is depressurized to low pressure and flowing through the first evaporator 5 evaporated by absorbing heat. The first expansion organ 6 also serves to limit the mass flow of the refrigerant necessary to achieve a desired overheating of the refrigerant at the outlet of the evaporator 5 adjust. The second expansion organ 13 of the second evaporator 12 is closed. The second evaporator 12 is not charged with refrigerant.

In 3 is the thermal system 1 when operating in refrigeration mode for the supply air of the passenger compartment, similar to that in 2 shown operating mode, and a cooling mode of components of the powertrain.

Unlike the operating mode after 2 are both the first organ of expansion 6 of the first evaporator 5 as well as the second expansion organ 13 of the second evaporator 12 open, so that the mass flow of the refrigerant in a partial mass flow through the first flow path 7 and a partial mass flow through the second flow path 11 divided and relaxed each at low pressure level. Also the second expansion organ 13 serves the necessary limitation of the mass flow of the refrigerant to a desired overheating of the refrigerant at the outlet of the evaporator 12 adjust. The refrigerant is respectively flowing through the evaporator 5 . 12 evaporated by absorbing heat. The partial mass flows through the flow paths 7 . 11 be at the confluence point 9 mixed. The flow paths 7 . 11 and with it the evaporators 5 . 12 are charged in parallel with refrigerant.

The coolant of the coolant circuit is between the heat exchanger 25 the components of the powertrain and as the evaporator 12 of the refrigerant circuit 2 operated refrigerant-refrigerant heat exchanger 12 circulated so that in the heat exchanger 25 Heat dissipated by the components of the drive train and absorbed by the coolant heat in the refrigerant-refrigerant heat exchanger 12 completely transferred to the refrigerant.

Out 4 goes the thermal system 1 when operating in a heat pump mode or heating mode for heating the supply air of the passenger compartment while receiving heat from the ambient air. The condition of the air conditioner 30 in the flow direction 37a Guided supply air for the passenger compartment becomes when overflowing the heat transfer surface of the second refrigerant-air heat exchanger 5 not changed. The third refrigerant air heat exchanger 14 is supplied with the supply air, which through the first flow channel 34 and thus over the heat transfer surfaces of the heat exchanger 14 . 35 is directed. In the third refrigerant-air heat exchanger 14 Heat is transferred from the refrigerant to the supply air for the passenger compartment. The supply air is heated. With commissioning of the additional heating heat exchanger 35 the supply air can be further heated. The louver 33 is the second flow channel 36 arranged close.

When flowing through between the third refrigerant-air heat exchanger 14 and the first refrigerant-air heat exchanger 4 arranged third expansion element 15 the refrigerant is expanded from the high pressure level to the low pressure level and when flowing through the first refrigerant-air heat exchanger operated as an evaporator 4 taking in heat from the downstream direction 37b Guided ambient air evaporates. The bypass flow path 16 is closed and is not flowed through by refrigerant. The refrigerant flows independently of the respective operating mode in the same direction through the first refrigerant-air heat exchanger 4 ,
Depending on the prevailing conditions, in particular the values of the air temperatures of the environment and in the passenger compartment or the cooling requirement of the components of the drive train, the mass flow of the refrigerant with the help of the positions of the expansion organs 6 . 13 the evaporator 5 . 12 on the flow paths 7 . 11 divided up.
In operating mode after 4 is the first organ of expansion 6 of the first evaporator 5 closed. The first evaporator 5 is not charged with refrigerant. The second expansion organ 13 of the second evaporator 12 is fully open so that the refrigerant is the expansion organ 13 happens without pressure loss. The refrigerant flows through then the second evaporator 12 without absorbing heat. The second evaporator 12 In addition, it is not possible to operate with coolant.

5 shows the thermal system 1 when operating in a heat pump mode or heating mode for heating the supply air of the passenger compartment and a cooling mode of components of the drive train, that is, by absorbing heat of the components of the drive train. Unlike the operating mode after 4 It is not the ambient air that serves as the heat source for the refrigerant, but the components of the powertrain. The operation within the air conditioner 30 stays unchanged.
The main difference of operating modes after 4 and 5 lies in the circuit of the second expansion element 13 and the third expansion organ 15 , The third expansion organ 15 is closed, so that the first refrigerant-air heat exchanger 4 is not charged with refrigerant. The valve 19 of the bypass flow path 16 it is open. The total mass flow of the high pressure refrigerant is through the bypass flow path 16 directed.
When flowing through the second expansion element 13 the refrigerant is released from the high pressure level to the low pressure level and flows through the operated as an evaporator refrigerant-refrigerant heat exchanger 12 under the absorption of heat from the components of the drive train, in particular the battery, evaporated.

The coolant circuit for controlling the temperature of the components of the drive train may, for example, be connected on the one hand for active cooling of the battery. On the other hand, the coolant circuit may be switched to use the waste heat of other electronic components, such as the electric motor, the power electronics or the charger as a heat source.

In 6 is the thermal system 1 shown operating in a Nachheizmodus for the supply air of the passenger compartment. In doing so, the refrigerant circuit becomes 2 as in operation in the cooling system mode for the supply air of the passenger compartment 2 flows through the refrigerant.
The main difference of operating modes after 2 and 6 lies in the setting of the louver 33 inside the air conditioner 30 , The by the air conditioner 30 in the flow direction 37a Guided supply air for the passenger compartment becomes when overflowing the heat transfer surface of operated as an evaporator second refrigerant-air heat exchanger 5 cooled and dehumidified. The louver 33 is the first flow channel 34 arranged at least partially opening, so that the cooled and dehumidified mass flow of the air into a first partial mass flow through the first flow channel 34 with the third refrigerant-air heat exchanger 14 and a second partial mass flow through the second flow channel 36 is split. This is in the third, operated as a condenser / gas cooler refrigerant air heat exchanger 14 Transfer heat from the refrigerant to the supply air. The previously cooled and dehumidified supply air is reheated.
That between the third refrigerant-air heat exchanger 14 and also operated as a condenser / gas cooler first refrigerant-air heat exchanger 4 arranged third expansion organ 15 is fully open so that the refrigerant is the expansion organ 15 happens without pressure loss. A first part of the refrigerant from the refrigerant circuit 2 heat to be dissipated is consequently flowing through the third refrigerant-air heat exchanger 14 transferred to the supply air for the passenger compartment, while a second part of the refrigerant from the refrigerant circuit 2 dissipated heat when flowing through the first refrigerant-air heat exchanger 4 to the flow direction 37b Guided ambient air is released without affecting the target temperature of the supply air for the passenger compartment. The bypass flow path 16 is closed and is not flowed through by refrigerant.
Part of the flow through the first evaporator 5 During the evaporation of the refrigerant from the refrigerant to low pressure level recorded heat can then be used to reheat the supply air for the passenger compartment.

Alternatively, the pressure level of the refrigerant within the first refrigerant-air heat exchanger 4 depending on the temperature of the ambient air by means of the third expansion element 15 be managed. In this case, for example, a below the temperature of the ambient air corresponding pressure of the refrigerant can be adjusted to the first refrigerant-air heat exchanger 4 to operate as an evaporator and to absorb heat from the ambient air. Or a pressure of the refrigerant corresponding to the temperature of the ambient air is set, so that no heat is transferred. The corresponding pressure level is adjusted by means of the expansion organs 6 . 15 set.

7 shows the thermal system 1 when operating in a post-heating mode for the supply air of the passenger compartment, similar to that in 6 illustrated mode of operation, as well as a cooling mode of components of the drive train, that is, by absorbing heat of the components of the drive train. The operation within the air conditioner 30 stays unchanged.
Unlike the operating mode after 6 is the third organ of expansion 15 closed, so the first refrigerant-air heat exchanger 4 is not charged with refrigerant. The valve 19 of the bypass flow path 16 it is open. The total mass flow of the high pressure refrigerant is through the bypass flow path 16 directed. As a result, no heat is transferred between the refrigerant and the ambient air. In addition, both are the first expansion organ 6 of the first evaporator 5 as well as the second expansion organ 13 of the second evaporator 12 open, so that the mass flow of the refrigerant in a partial mass flow through the first flow path 7 and a partial mass flow through the second flow path 11 divided and relaxed each at low pressure level. The refrigerant is respectively flowing through the evaporator 5 . 12 evaporated by absorbing heat. The partial mass flows through the flow paths 7 . 11 be at the confluence point 9 mixed. The flow paths 7 . 11 and with it the evaporators 5 . 12 are charged in parallel with refrigerant. The components of the powertrain and the supply air for the passenger compartment are the only sources of heat. In each case, the amounts of heat to be absorbed are set as required or priority-controlled.

Out 8th goes the thermal system 1 when operating in a rehousing mode for the supply air of the passenger compartment and a cooling mode of components of the drive train, that is, by absorbing heat of the components of the drive train, similar to that in 7 illustrated operating mode, with additional transfer of heat between the refrigerant and the ambient air, similar to the in 6 shown operating mode, forth. The operation within the air conditioner 30 remains unchanged.
Unlike the operating mode after 6 are both the first organ of expansion 6 of the first evaporator 5 as well as the second expansion organ 13 of the second evaporator 12 open, so that the mass flow of the refrigerant in a partial mass flow through the first flow path 7 and a partial mass flow through the second flow path 11 divided and relaxed each at low pressure level. The refrigerant is respectively flowing through the evaporator 5 . 12 evaporated by absorbing heat. The partial mass flows through the flow paths 7 . 11 be at the confluence point 9 mixed. The flow paths 7 . 11 and with it the evaporators 5 . 12 are charged in parallel with refrigerant.
The components of the powertrain and the supply air for the passenger compartment serve as heat sources for the refrigerant circuit. In each case, the amounts of heat to be absorbed are set as required or priority-controlled. Depending on the adjustment of the expansion organs 6 . 13 . 15 can also be the first refrigerant-air heat exchanger 4 operated as a heat sink or heat source for the refrigerant. So can at fully open third expansion organ 15 a part of the refrigerant from the refrigerant circuit 2 dissipated heat when flowing through the first refrigerant-air heat exchanger 4 to the flow direction 37b discharged ambient air. Alternatively, the pressure level of the refrigerant may be adjusted to a value corresponding to the temperature of the ambient air, to the first refrigerant-air heat exchanger 4 operate as an evaporator and absorb heat from the ambient air or it is adjusted to the temperature of the ambient air pressure of the refrigerant, so that no heat is transmitted.

9 shows the thermal system 1 when operating in a defrosting mode of the first refrigerant-air heat exchanger operated in this mode as a condenser / gas cooler 4 which is applied when operating the system 1 For example, in one of the previously described modes due to a malfunction or due to an overload of the heat pump mode or Nachheizmodus, in which the first refrigerant-air heat exchanger 4 as an evaporator to absorb heat in the refrigerant circuit 2 is operated while keeping the heat transfer surface of the heat exchanger 4 icy. With the at the heat transfer surface of the heat exchanger 4 formed ice layer reduces the heating power of the system 1 , The system 1 is operated inefficiently. To the on the heat transfer surface of the heat exchanger 4 To eliminate formed ice, becomes the first refrigerant-air heat exchanger 4 despite heating demand for the supply air of the passenger compartment operated as a condenser / gas cooler and charged with refrigerant to a high pressure level. With the release of heat by the refrigerant, the at the heat transfer surface of the heat exchanger 4 Defrosted ice formed.
That between the third refrigerant-air heat exchanger 14 and operated as a condenser / gas cooler first refrigerant-air heat exchanger 4 arranged third expansion organ 15 is fully open so that the refrigerant is the expansion organ 15 happens without pressure loss. At least a first part of the refrigerant from the refrigerant circuit 2 dissipated heat is in the first refrigerant-air heat exchanger 4 used to defrost the ice layer. A second part of the refrigerant from the refrigerant circuit 2 dissipated heat can flow through the third refrigerant-air heat exchanger 14 to the flow direction 37a through the air conditioner 30 subsidized supply air for the passenger compartment are transmitted. Here is the louver 33 the first flow channel 34 arranged close. Around To speed up the process of defrosting can also remove all of the refrigerant from the refrigerant circuit 2 dissipated heat in the first refrigerant-air heat exchanger 4 be used to defrost the ice layer. Thereby, no air mass flow through the air conditioner 30 directed. The bypass flow path 16 is always closed and is not flowed through by refrigerant.
The first expansion organ 6 of the first evaporator 5 closed. The first evaporator 5 is not charged with refrigerant. The state of an operating mode dependent by the air conditioner 30 in the flow direction 37a Guided supply air for the passenger compartment becomes when overflowing the heat transfer surface of the second refrigerant-air heat exchanger 5 not changed. When flowing through the operated as an evaporator refrigerant-coolant heat exchanger 12 The refrigerant is vaporized by absorbing heat from the components of the powertrain. The components of the drive train thus serve as a heat source for defrosting the first refrigerant-air-heat exchanger 4 ,
Depending on requirements and operating mode, commissioning of the additional heating heat exchanger can be carried out 35 the supply air is heated or further heated.

In 10 is the thermal system 1 when operating in a cooling mode of powertrain components similar to that in FIG 3 shown operating mode shown.
Unlike the operating mode after 3 the refrigerant is only in the second expansion element 13 of the second evaporator 12 Relaxed at low pressure level and when flowing through the second evaporator 12 evaporated by absorbing heat. The first expansion organ 6 of the first evaporator 5 is closed. The first evaporator 5 is not charged with refrigerant. In addition, no air mass flow through the air conditioner 30 promoted.
This is also the third refrigerant-air heat exchanger 14 no heat dissipated from the refrigerant. That between the third refrigerant-air heat exchanger 14 and operated as a condenser / gas cooler first refrigerant-air heat exchanger 4 arranged third expansion organ 15 is fully open so that the refrigerant is the expansion organ 15 happens without pressure loss. The refrigerant from the refrigerant circuit 2 dissipated heat is in the first refrigerant-air heat exchanger 4 completely to the flow direction 37b transmitted ambient air transmitted. The bypass flow path 16 is closed and is not flowed through by refrigerant.
The coolant of the coolant circuit is between the heat exchanger 25 the components of the powertrain and as the evaporator 12 of the refrigerant circuit 2 operated refrigerant-refrigerant heat exchanger 12 circulated so that in the heat exchanger 25 Heat dissipated by the components of the drive train and absorbed by the coolant heat in the refrigerant-refrigerant heat exchanger 12 completely transferred to the refrigerant.

The thermal system 1 is primarily operated during a charging operation of the battery to a charging station in the cooling mode of the components of the drive train.

The in the 2 to 10 at the embodiment of the system 1 to 1 described operating modes can also with the in the 11 to 13 shown thermal systems 1a . 1b . 1c be represented, which in each case by the formation of an internal heat exchanger 24a . 24b . 24c in the refrigerant circuit 2a . 2 B . 2c differ.

11 shows a thermal system 1a with a refrigerant circuit 2a for conditioning the supply air for the passenger compartment and cooling components of the drive train of a motor vehicle.
The internal heat exchanger 24a is high pressure side between the confluence 18 of the bypass flow path 16 of the first refrigerant-air heat exchanger 4 and the branch office 8th the flow paths 7 . 11 the evaporator 5 . 12 and thus in the flow direction of the refrigerant directly in front of the expansion organs 6 . 13 the operated as an evaporator second refrigerant-air heat exchanger 5 and refrigerant-refrigerant heat exchangers 12 arranged. Low pressure side is the inner heat exchanger 24a within the first flow path 7 after operated as an evaporator second refrigerant-air heat exchanger 5 educated.
With the arrangement of the internal heat exchanger 24a the entire flows in the refrigerant circuit 2a circulating mass flow of the refrigerant through the high pressure side region of the inner heat exchanger 24a while the internal heat exchanger 24a low pressure side only with the through the first flow path 7 directed mass flow of the refrigerant is applied.

In 12 a thermal system 1b with a refrigerant circuit 2 B , similar to the system 1a out 11 shown. Unlike the system 1a , in particular to the refrigerant circuit 2a , out 11 is the internal heat exchanger 24b high-pressure side between the first refrigerant-air heat exchanger 4 and the confluence point 18 of the bypass flow path 16 of the first refrigerant-air heat exchanger 4 arranged. This is the inner heat exchanger 24b high pressure side so in the refrigerant circuit 24b involved that one through the bypass flow path 16 directed mass flow of the refrigerant to the inner heat exchanger 24b flows around while the internal heat exchanger 24b low pressure side with the through the first flow path 7 directed mass flow of the refrigerant is applied.

Out 13 goes a thermal system 1c with a refrigerant circuit 2c , similar to the system 1a out 11 , forth. Unlike the system 1a , in particular to the refrigerant circuit 2a , out 11 is the internal heat exchanger 24c both high pressure side and low pressure side within the first flow path 7 arranged so that the inner heat exchanger 24c on both sides only with the through the first flow path 7 directed mass flow of the refrigerant is applied. The internal heat exchanger 24c is high pressure side between the branch point 8th the flow paths 7 . 11 and the first expansion organ 6 as well as low-pressure side after the operated as an evaporator second refrigerant-air heat exchanger 5 educated.

The internal heat exchanger 24a . 24b . 24c Among other things, it serves to reduce the power of the compressor 3 especially during operation of the system 1a . 1b . 1c in refrigeration system mode. In addition, the specific cooling capacity of the operated as an evaporator second refrigerant-air heat exchanger 5 compared to the specific cooling capacity of the operated as an evaporator refrigerant-refrigerant heat exchanger 12 in favor of the comfort in the passenger compartment without structural alteration of the air conditioner 30 elevated.
With the formation of the internal heat exchanger 24a . 24b . 24c be the efficiency of the operation of the system 1a . 1b . 1c compared to the system 1 and by reducing the power requirement of the electric compressor 3 the purely electrical range of the respective motor vehicle increases.

LIST OF REFERENCE NUMBERS

1, 1a, 1b, 1c

system

2, 2a, 2b, 2c

Refrigerant circulation

3

compressor

4

first refrigerant-air heat exchanger

5

second refrigerant-air heat exchanger, first evaporator

6

first expansion organ

7

first flow path

8th

branching point

9

opening point

10

check valve

11

second flow path

12

Refrigerant-refrigerant heat exchanger, second evaporator

13

second expansion organ

14

third refrigerant air heat exchanger, condenser / gas cooler

15

third expansion organ

16

Bypass flow path of the first refrigerant-air heat exchanger 4

17

branching point

18

opening point

19

Valve

20

check valve

21

accumulator

22a, 22b, 22c

Pressure-temperature sensor

23a, 23b

Temperature Sensor

24a, 24b, 24c

internal heat exchanger

25

Heat exchanger components powertrain

30

air conditioning

31

casing

32

fan

33

Cowl

34

first flow channel

35

Additional heating exchangers

36

second flow channel, bypass

37a

Flow direction supply air

37b

Flow direction ambient air

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102017114136 A1 [0010]

Claims (16)

A thermal system (1, 1a, 1b, 1c) for conditioning the supply air for a passenger compartment and for cooling components of a drive train of a motor vehicle, comprising a refrigerant circuit (2, 2a, 2b, 2c) - A compressor (3), a first refrigerant-air heat exchanger (4) for transmitting heat with ambient air, which is designed to operate as a condenser / gas cooler and evaporator, operated as a first evaporator second refrigerant-air heat exchanger (5) an upstream first expansion element (6) and a second heat exchanger (12) operated as a second evaporator with an upstream second expansion element (13), - A operated as a condenser / gas cooler third refrigerant-air heat exchanger (14) for heating the supply air for the passenger compartment and a third expansion element (15) which between the compressor (3) and the first refrigerant-air heat exchanger (4) are, wherein the third expansion member (15) is formed downstream of the third refrigerant-air heat exchanger (14) in the flow direction of the refrigerant. Thermal system (1, 1a, 1b, 1c) according to Claim 1 characterized in that the second refrigerant-air heat exchanger (5) with the first expansion element (6) within a first flow path (7) and the heat exchanger (12) with the second expansion element (13) within a second flow path (11) of the Refrigerant circuit (2) are arranged, which in each case from a branch point (8) to an outlet point (9) extending, arranged parallel to each other and, depending on the need, individually or in parallel with each other are acted upon with refrigerant. Thermal system (1, 1a, 1b, 1c) according to Claim 1 or 2 characterized in that the refrigerant circuit (2, 2a, 2b, 2c) has a bypass flow path (16) around the first refrigerant-air heat exchanger (4) extending from a branch point (17) to an orifice (18) ) extending, is arranged parallel to the first refrigerant-air heat exchanger (4). Thermal system (1, 1a, 1b, 1c) according to Claim 3 , characterized in that the branching point (17) between the third refrigerant-air heat exchanger (14) and the third expansion element (15) is arranged. Thermal system (1, 1a, 1b, 1c) according to Claim 3 or 4 , characterized in that within the bypass flow path (16) is formed a valve (19) for opening and closing the bypass flow path (16). Thermal system (1, 1a, 1b, 1c) according to one of Claims 3 to 5 , characterized in that the branching point (17) is designed as a combined three-way valve with expansion functionality in the direction of the first refrigerant-air heat exchanger (4) and with shut-off functionality in the direction of the bypass flow path (16). Thermal system (1, 1a, 1b, 1c) according to one of Claims 1 to 6 , characterized in that the heat exchanger (12) operated as a second evaporator is designed as a refrigerant-coolant heat exchanger (12) and is arranged within a coolant circuit which has a heat exchanger (25) for cooling the components of the drive train. Thermal system (1a, 1b, 1c) according to one of Claims 2 to 7 characterized in that the refrigerant circuit (2a, 2b, 2c) is formed with an internal heat exchanger (24a, 24b, 24c) for heat transfer between the refrigerant at high pressure and the refrigerant at low pressure, the internal heat exchanger (24a, 24b, 24c ) is arranged on the low pressure side within the first flow path (7) in the flow direction of the refrigerant after the second refrigerant-air heat exchanger (5) operated as an evaporator. Thermal system (1a) according to one of Claims 3 to 8th , characterized in that the refrigerant circuit (2a) is formed with an internal heat exchanger (24a) for heat transfer between the refrigerant at high pressure and the refrigerant at low pressure, wherein the internal heat exchanger (24a) low pressure side within the first flow path (7) in the flow direction of the Refrigerant after the operated as an evaporator second refrigerant-air heat exchanger (5) and the high pressure side between the discharge point (18) of the bypass flow path (16) and the branch point (8) of the flow paths (7, 11) is arranged. Thermal system (1b) according to one of Claims 3 to 8th characterized in that the refrigerant circuit (2b) is formed with an internal heat exchanger (24b) for heat transfer between the refrigerant at high pressure and the refrigerant at low pressure, wherein the internal heat exchanger (24b) low pressure side within the first flow path (7) in the flow direction of the Refrigerant after the operated as an evaporator second refrigerant-air heat exchanger (5) and the high-pressure side between the first refrigerant-air heat exchanger (4) and the discharge point (18) of the bypass flow path (16) is arranged. Thermal system (1c) after Claim 8 , characterized in that the inner heat exchanger (24c) is arranged on the high pressure side within the first flow path (7) in the flow direction of the refrigerant upstream of the first expansion element (6). A method for operating a thermal system (1, 1a, 1b, 1c) of a motor vehicle for operation in a refrigeration system mode, in a heat pump mode and in a reheating mode for the supply air to be conditioned of a passenger compartment according to one of Claims 1 to 11 characterized in that the refrigerant when operating in a heat pump mode or Nachheizmodus for heating the supply air of the passenger compartment when flowing through between the third refrigerant-air heat exchanger (14) and the first refrigerant-air heat exchanger (4) arranged third expansion element (15 ) is expanded from a high pressure level to a low pressure level and vaporized while flowing through the evaporator operated as the first refrigerant-air heat exchanger (4) while absorbing heat from the ambient air, wherein when flowing through the third refrigerant-air heat exchanger (14) heat from the refrigerant is transmitted to the supply air for the passenger compartment. Method according to Claim 12 , characterized in that a mass flow of the refrigerant by completely opening the second evaporator operated as the second refrigerant-air heat exchanger (5) and / or the second evaporator operated heat exchanger (12) upstream expansion element (6, 13) without pressure loss to the compressor (3). A method for operating a thermal system (1, 1a, 1b, 1c) of a motor vehicle for operation in a refrigeration system mode, in a heat pump mode and in a reheating mode for the supply air to be conditioned of a passenger compartment according to one of Claims 3 to 11 characterized in that the refrigerant when operating in a heat pump mode or Nachheizmodus for heating the supply air of the passenger compartment through the bypass flow path (16) is passed and when flowing through the first evaporator operated second refrigerant air heat exchanger (5) taking up Heat from the supply air and / or operated as a second evaporator heat exchanger (12) is vaporized by absorbing heat from the components of the drive train, wherein when flowing through the third refrigerant-air heat exchanger (14) heat from the refrigerant to the supply air for the passenger compartment is transmitted. Method according to Claim 12 or 14 , characterized in that a mass flow of the refrigerant by position of the first evaporator operated second refrigerant-air heat exchanger (5) and the second evaporator operated heat exchanger (12) upstream expansion elements (6, 13) on the heat exchanger (5, 12 ) is split to absorb heat from the supply air for the passenger compartment and / or components of the drive train. Use of a thermal system (1, 1a, 1b, 1c) according to one of Claims 1 to 11 as an air conditioning system of a motor vehicle for conditioning supply air for a passenger compartment and for conditioning components of the drive train and electronic components.

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